Question 805762
boat   	speed	x   	kph														
current     	speed	3	kph														
																	
against	current     	x-	3	kph													
with	current     	x+	3	kph													
																	
Distance=	2	miles															
																	
Time against + time with  =			10	hours													
t=d/r																	
																	
2	/(	x   	+	3	)	+	2	/(x	-	3	)	=	10				
																	
LCD =	(x	-	3	)	(	x   	+	3	)								
2	*(	x   	-	3	)	+	2	(x	+	3	)	=	10	(x^2	-	9	)
2	x   	-	-6	+	2	x   	+	6		=	10	(	x ^2		-	9	)
4	x   	=	10	x ^2		-90											
10	x ^2	-	-4	x   	-	90	=	0									
																	
Find the roots of the equation by quadratic formula															5.12		
			iiiii														
a=	10	,	b=	-4	,	c=	-90										
																	
b^2-4ac=	16	+	3600														
b^2-4ac=	3616																
{{{	sqrt(	3616	)=	60.13	}}}												
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}																	0
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}																	
x1=(	4	+	60.13	)/	20												
x1=	3.21																
{{{x2=(-b-sqrt(b^2-4ac))/(2a)}}}																	
x2=(	4	-60.13	) /	20													
x2=	-2.81																
Ignore negative value																	
boat   	speed	3.207	kph